Western Flyer completes MBARI's
first expedition
to Juan de Fuca Ridge

The
research vessel
Western Flyer and remotely operated vehicle Tiburon recently
completed a 12-day geological and geochemical expedition to the southern
portion of the Cleft segment of the Juan de Fuca ridge, some 300 km (~200
miles) from Newport, Oregon. Tiburon also dove at Axial
Caldera.

Special geological sampling equipment was integrated on Tiburon
for the first time, including a drillsled for coring vertical rock faces,
wax cores for basalt glass sampling, and geocompass and magnetometer
instruments. A total of 137 geological samples and approximately 700
biological samples were collected by Tiburon. The above photo shows
a sample of hydrothermal vent tubeworms in Tiburon's manipulator
arm.

The volcanically active Juan de Fuca Ridge is known
for its dynamic geology and awe-inspiring hydrothermal vents. New ocean
crust is being formed at this mid-ocean ridge. This
expedition was MBARI's first to this region. The image on the left shows a
high temperature hydrothermal vent. The black "smoke" emerging
from the vent is composed of minerals precipitating out of solution as the
hot water (more than 300° C) cools upon contact with the cold seawater.

The mission's chief scientist, MBARI geologist Debra
Stakes, was joined by Michael Perfit of the
University
of Florida (basalt geochemistry) and Maurice Tivey of the
Woods
Hole Oceanographic Institution (magnetics). MBARI Postdoctoral Fellow Thomas Chapin
managed the instrument deployment/recovery dive at
Axial Caldera. Other members of the shipboard scientific party were all
from MBARI. These included Karen Salamy who was responsible for the Tiburon
drillsled and for the archival of all geological samples. Tony Ramirez was
responsible for navigation and post-dive data. Greg Moretti (summer
intern) was responsible for sample photography and daily
cruise reports for the web. Josh Plant worked with Chapin to prepare
the instruments and analyze fluids from Axial Caldera. Robby Young was the
shipboard biologist who collected both vent and non-vent specimens.
Perfit supervised the night wax coring program with assistance from
Stakes, Chapin, Plant, Salamy, Ramirez and Moretti.

A drainback
supported by lava columns. Drainbacks are geologic formations that
form when lava recedes after a flow.

This lava pillar is also a
drainback feature. Lava pillars are formed around vents that ejected
gases when active.

This geological feature is
called a "skylight," a window for researchers into a lava
tube system.